A NEW breath test can tell doctors if patients with suspected stomach ulcers are harbouring the bacterium Helicobacter pylori. Scientists now believe that this bug is the underlying cause of many uclers and must be eliminated if the condition is to be permanently cured.

They say that a combination of antibiotics and a substance called bismuth is an effective treatment. Until recently, the only way to discover whether a patient had H. pylori in his or her stomach was by an unpleasant investigation known as an endoscopy, which involves putting a tube down the patient's throat and taking a biopsy of the stomach. The new breath test tells doctors if the bacterium is present by measuring the presence of urea, a waste product of the breakdown of proteins. It is simple, reliable and a great deal more pleasant for the patient.